Random itching?

I've never really had problems with my skin, no chronic conditions, no allergies, nothing. But about two weeks ago, my feet started itching. It started moving up to my legs. After about a week of itching, my chest broke out in a nonpruritic rash, and it spread to my neck and face. I took some antihistamines and used some cortisone cream and the rash on my chest cleared up after a day or two, but the itching on my legs and feet didn't. What throws me is that it's not really a rash on my legs, it's just itchy. It only gets red and inflamed when I scratch. So throughout the next week, it spread to my arms, and now it's spreading to my back and abdomen. I've still been using antihistamines like clockwork, claratin during the day and benadryl at night. I sleep ok at night only because benadryl knocks me out. But it's the same everywhere.. No rash, just unbearable itching. I had to call into work today because I couldn't function. The claratin doesn't really do much, and the cortisone cream only soothes for about 5 minutes. I started using an external analgesic, but that stops working after about 5 minutes, too. I plan on going to the doctor as soon as I can get an appointment, but anyone have any idea what it could be? I thought fungal, but I've had athletes foot for years and it's never spread up from my feet like that. And there's also the lack of rash. I ruled out scabies for the same reason. I did notice today that after I would scratch a lot, little red bumps broke out, though. Anyway, no new detergents, soaps, lotions, medicines, or strange foods. I bought an oatmeal lotion and started moisturizing as soon as I started having trouble, and I tried oatmeal baths. Nothing. Anyone got any suggestions for relief while I wait for an appointment? I'm gonna need to go to school Monday and I'm not lookin forward to it feeling like this... I'm bruising myself from scratching so hard :/
Thanks!

Thanks, I'll try Zyrtec.
I actually have considered that.. I've never had any problems with scented lotions before, so I'm not sure why my skin is freaking out so much over a non-scented one, but I've stopped moisturizing all the same. But I've still been using Calahist or Calamine, because I just need some soothing even if it's only for 10 minutes. I've considered that it might be spreading with the ointments if it's fungal, but I just can't handle the itching enough to stop using it.. I'll see my doctor ASAP.

Well, I've found the answer to the problem. After more thorough investigation, I found bed bugs under my mattress. But I don't see a lot of the classic signs of bed bug bites.. three in a row, etc. I guess maybe they bit me in a few places and I had an allergic reaction to their saliva? It looks more like a rash on my arms now, not like bed hug bites. So I don't know. But hopefully once I get rid of the bugs, the rash will go away. I'm doing the baking soda paste to try and soothe it later today.. anyone have any other suggestions?

Bed bugs are tricky to eliminate. Definitely, every bit of bedding needs to be washed and dried. If something can't be easily washed, just sticking it in a dryer on HIGH for 5-10 minutes should also kill bed bugs.

Don't spend money on a new mattress until you are sure the bugs are eliminated from the house.